Medical catheters have been used successfully for many years to access the blood stream of human and animal patients. Multi-lumen catheters are used for a variety of applications where it is necessary to have two or more separate fluid pathways. The purposes of accessing the blood circulatory system include introduction of medication, hemodialysis therapy, plasmaphoresis therapy, and other therapies which may require access to the blood circulatory system.
In the case of hemodialysis, a dual-lumen catheter can be employed to simultaneously accommodate opposing blood flow. One lumen aspirates blood from a blood vessel of a patient to a dialysis machine where it is processed for the removal of toxins, while the other lumen infuses the purified blood to the patient.
A problem in many dialysis catheters is clotting and fibrin sheath formation around the “arterial” inlet used for aspiration of blood from a patient. Thrombus and fibrin can occlude distal tips or other places throughout the length of the catheter lumens, resulting in loss of catheter function when such an occlusion prevents blood flow. Usually, catheters have one large exposed hole or one large hole with many little side holes. The thought process is that the extra holes will prevent the inlet from sucking up against the blood vessel wall. Unfortunately, the small holes become filled with fibrin and the large inlet hole develops a trap door clot, which makes the catheter useless. A secondary problem is that related to the arterial lumen “sucking” against the vessel wall in which it resides. This problem can occur if the arterial lumen ports become fully occluded by the patient's vasculature. A technique to resolve such problem is to reverse the bloodlines (i.e., to aspirate through the longer lumen, and to infuse through the shorter lumen, contrary to normal therapeutic pump blood flow). This causes cleaned blood to flow directly toward the lumen that is under vacuum, line reversal in certain catheters can result in inefficient flow and (high re-circulation).
Additionally, there are major side effects which carry patient safety issues, such as hemorrhaging due to the use of indwelling anticoagulants. These anticoagulants are used when the catheter is not being utilized. Side effects of these anticoagulants, primarily heparin, cause acute and chronic gastrointestinal bleeding, retinopathy, and anemia.
Another major issue is that of infection. Currently, catheters on the market use only one single cuff immediately beneath the skin, which is expected to anchor the catheter into the patient's tissue, as well as provide blockage to motile bacteria. This cuff design is often inadequate to perform these functions.
The present invention solves many of the above problems associated with catheters as will become apparent in reading the following hereinafter.